The invention relates to a device for removing foam and polluting light solid substances with high surface tension.
The device is applicable as a separator of foam and polluting solid substances found in freshwater, brackish and salt water environments, generally quite shallow, such as for example ponds or small lakes, either closed or semi-closed, in which processes of oxygenisation or mechanical mixing of waters is done, which operations generate foamy suspensions, or where there might be solid polluting substances, such as for example feathers, or twigs, or algae, or leaves, which remain in the water as the environment is a closed one.
The prior art teaches a patent application, Italian patent RE2002A000015, entitled “A Device for Foam Removal”, filed by the same applicant and concerning a device having a like aim to that of the present application.
The above application, having been installed in appropriate environments, has displayed a number of drawbacks connected with both the conformation and the positioning, internally of the device, of a rotating organ, acting as a means of separation of the liquid foam, both in relation to the presence of solid polluting substances, or feathers, twigs, algae or leaves, which mix up with the foam to be removed, and the impossibility of visually observing the state of repair and efficiency of the invention. The conformation of the known rotary separator organ is somewhat like the drum of a washing machine, or an upturned drinking beaker having perforated lateral walls terminating radially to configure a circular-crown recess.
The drum, which is located internally of the bearing structure, faces the inlet conduit of the polluting substances at a height at which the lateral walls which delimit the drum surround the outlet of the inlet conduit. The conformation of the drum and its positioning have a first disadvantage of trapping polluting solid substances inside the drum. The solid substances trapped within the drum can cause obstructions of the perforated lateral walls with a negative effect on the separation performance of the device, to a point where, following an excessive accumulation of the substances, imbalances in the rotation can lead to stress fatigue of the drum shaft.
The stage performed after breaking up the foam is their evacuation, through a drainage channel which uses the force of gravity to discharge, or might be provided with an outlet conduit which discharges by mechanical aspiration.
A further disadvantage of the above device of the prior art, in relation to the location of the drum internally of the bearing structure, is that it is not possible to keep a real-time check on the efficiency of the machine. Consequently, the noting of any faults might occur after the machine has stopped and the drum cover has been removed.
The main aim of the present invention is to realise a device that enables direct vision of the machine performance, i.e. the efficiency of the foam separation from the liquid.
A further aim of the invention is to adopt a rotary element which does not trap polluting solid elements, safeguarding the correct functioning of the machine.
A further aim is to realise a machine which enables maintenance and cleaning operations to be carried out on the rotary organ without having to laboriously strip the machine down.
These aims and advantages and more besides are all achieved by the invention as it is characterised in the appended claims.